Short-timescale variability of picophytoplankton abundance and cellular parameters in surface waters of the Alboran Sea (western Mediterranean)

The Alboran Sea (western Mediterranean) is characterized bya well-defined hydrological structure, the Almeria (Spain)–Oran(Algeria) geostrophic front. During the Almofront-2 cruise (November22, 1997 to January 18, 1998), high frequency sampling (     

Le traitement chirurgical des tumeurs endocrines digestives

Surgery is the only curative treatment for localized gastrointestinal endocrine tumors. It plays a major role in therapeutic strategy. It meets the oncological principles of treatment. It must take into consideration the site of the tumor, its extension and its secretory nature. In well-differentiated endocrine tumors according to WHO classification, surgery must be indicated, not only for the primary tumor but also for the metastasis, particularly liver metastasis. The primary gastrointestinal endocrine tumors (functional or non functional) are mainly pancreatic in origin but also can be situated in small bowel, appendix, colon, or rectum. Surgery is part of a comprehensive approach discussed in multidisciplinary meeting.     

Small fibronectin fragments induce endothelium-dependent vascular relaxations

Strips of rabbit thoracic aorta precontracted with phenylephrine relaxed when exposed to selected synthetic peptides derived from the cell attachment domain of fibronectin. The relaxations elicited by both acetylcholine and the hexapeptide Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) were dependent on the presence of an intact endothelium, were resistant to indomethacin, and were inhibited by hemoglobin. The structure-activity relationship of four oligopeptides derived from fibronectin was in fair agreement with their ability to prevent fibronectin-mediated cell adhesion in other experimental systems. Human plasma fibronectin (up to 2.3 microM) did not relax this preparation and did not prevent the relaxant effect of the synthetic hexapeptide GRGDSP. On the rabbit isolated mesenteric artery, the relaxations induced by GRGDSP were significantly inhibited by indomethacin treatment, suggesting a contribution of locally produced prostaglandins. The displacement of fibronectin by soluble peptides from its binding sites on endothelial cells may result in significant pharmacologic responses, probably resulting from perturbations of the endothelial cell membranes.     

The past, present and future of childhood malaria mortality in Africa

During the past few years, there has been a historic series of declarations of renewed commitment to malaria control in Africa. Whether the burden of malaria is increasing in Africa is a moot point. This article attempts to re-construct the evidence for the trends in childhood mortality as a result of Plasmodium falciparum infection over the last century in Africa.